hi,
as the page size is 4kb u need minimum of 12 bits to index into the
page... how come u got 9 bits... and there are 64*1024/4 pages... i.e 16K
pages... if each each page frame takes up 4 bytes also then we need to
get 64KB for the page table... am i missing something here...as none of
the answers has this value...
On Mon, 6 Jan 2003, Chandra G K Babu S wrote:
>
> the answer is 8mb, may be that is a one level page table.
> the page size is 4kb (=4k * 1/8 = 1/2kB)
> 32 bits of virtual address divided as 23+9,
> first 23 bits give the page number,
> the 9 bits give the index in a page. the page table have to
> accomdate (2 pow 23) entries so the page table size is 8 mb.
>
> i think this question ha nothing to do with the linux.
> any comments?
>
> with regards,
> kiran
> On Mon, 6 Jan 2003, Rupa wrote:
>
> >
> > Actually this was the question asked in some exam. I do no how to calculate
> > size of page table. They had given 4 answers...
> > i)16mb ii)8mb
> > iii)2mb iv) 24mb
> >
> > You have any idea?
> >
> > Regards,
> > Rupa
> > ----- Original Message -----
> > From: "Raghu R. Arur" <rra2002@cs.columbia.edu>
> > To: "Rupa" <rupa.ramakrishna@ionidea.com>
> > Sent: Monday, January 06, 2003 11:47 AM
> > Subject: Re: size of page table
> >
> >
> > >
> > > Hi,
> > >
> > > If you are talking about linux, the page table size is not related to the
> > > memory size (RAM size). page table is for per process and in linux each
> > > process will have 4GB of memory allocated. 3 GB for the user space and 1
> > > GB for the kernel space.
> > >
> > > HTH,
> > > raghu
> > >
> > > On Mon, 6 Jan 2003, Rupa wrote:
> > >
> > > > Hello,
> > > > I have small doubt regarding the sizeof page table. Consider a
> > machine with 64MB physical memory and a 32 bit virtual address space. If the
> > page size is 4kb, what is the approximate size of page table.?
> > > > Any help will be useful
> > > >
> > > > Rupa
> > > >
> > >
> >
> > --
> > Kernelnewbies: Help each other learn about the Linux kernel.
> > Archive: http://mail.nl.linux.org/kernelnewbies/
> > FAQ: http://kernelnewbies.org/faq/
> >
>
>
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